# \[PATCH 1/4\] video: msmfb: Put the partial update magic value into the fix\_screen struct. - From: Carl Vanderlip \ - Date: 2011-03-02 21:16:51 - List: linux-fbdev - Page: https://ratatoskr.run/linux-fbdev/2011/03/3684939 - Thread: https://ratatoskr.run/linux-arm-kernel/2011/03/3684937/t.md ```text From: Dima Zavin This can then be tested by userspace to see if the capability is supported. Userspace cannot rely on that value being left in var_screen, since userspace itself can change it. Signed-off-by: Dima Zavin Signed-off-by: Carl Vanderlip --- drivers/video/msm/msm_fb.c | 12 ++++++++++++ 1 files changed, 12 insertions(+), 0 deletions(-) diff --git a/drivers/video/msm/msm_fb.c b/drivers/video/msm/msm_fb.c index 5436aeb..fe5efe5 100644 --- a/drivers/video/msm/msm_fb.c +++ b/drivers/video/msm/msm_fb.c @@ -469,6 +469,18 @@ static void setup_fb_info(struct msmfb_info *msmfb) fb_info->var.yoffset = 0; if (msmfb->panel->caps & MSMFB_CAP_PARTIAL_UPDATES) { + /* + * Set the param in the fixed screen, so userspace can't + * change it. This will be used to check for the + * capability. + */ + fb_info->fix.reserved[0] = 0x5444; + fb_info->fix.reserved[1] = 0x5055; + + /* + * This preloads the value so that if userspace doesn't + * change it, it will be a full update + */ fb_info->var.reserved[0] = 0x54445055; fb_info->var.reserved[1] = 0; fb_info->var.reserved[2] = (uint16_t)msmfb->xres | -- Sent by an employee of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum. ```